Hydraulic acting jet gun for perforating well casings



June 12, 1956 N, JONES 2,749,841

HYDRAULIC ACTING JET GUN FOR PERFORATING WELL CASINGS Filed Aug. 51, 1950 2 Sheets-Sheet 1 W- 54 Fl.21 1:

l cc 54 56 1 t' 3 \l I 3 E iV-Jmm IN VEN TOR.

E. N. JONES June 12, 1956 HYDRAULIC ACTING JET GUN FOR PERFORATING WELL CASINGS 2 Sheets-Sheet 2 Filed Aug. 31, 1950 INVENTOR.

HYDRAULIC ACTING JET GUN FOR PERFORATING WELL CASINGS Edward N. Jones, Pettus, Tex.

Application August 31, 1950, Serial No. 182,515

7 Claims. (Cl. 10221.8)

This invention relates to new and useful improvements in apparatus for perforating well casings and is an improvement over my copending application, Serial No. 173,307, filed July 12, 1950.

The primary object of the present invention is to provide an explosive chamber that is lowered into a casing and supporting a plurality of slidable jet shots or explosive cartridges that are moved from the chamber and into close contact with the inner wall of a casing through the medium of a novel and improved hydraulic means.

Another important object of the present invention is to provide a device for perforating well casing and the like involving a cam actuated plunger that will puncture a gas filled tube and thereby permit gas released from the tube to be utilized for moving explosive charges into engagement with the inner wall of a well casing.

Yet another object of the present invention is the provision of an apparatus for perforating well casings which may be safely raised without exploding the charges even though the charges have been moved into contact with the wall of a casing.

A further object of the present invention is to provide a device of the aforementioned character wherein the hollow member may be used repeatedly, since the jet shots or charges may be readily replaced in a minimum time as well as the gas filled tube that is used for moving the jet shots radially from the hollow member.

A still further aim of the present invention is to provide a jet gun for perforating or puncturing well casings and the like that is simple and practical in construction, eificient and reliable in use, inexpensive to manufacture and operate, and otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming part hereof, wherein like numerals refer to like parts fliroughout, and in which:

Figure 1 is a longitudinal vertical sectional view of device according to the present invention being lowered in a well casing (shown in section);

Figure 2 is a View similar to Figure 1 but showing the plunger puncturing the gas filled tube and the explosive cartridges moved against the inner wall of the Well casing;

Figure 3 is an enlarged transverse horizontal sectional view taken substantially on the plane of section line 3-3 of Figure 1;

Figure 4 is an enlarged transverse horizontal sectional view taken substantially on the plane of section line 4-4 of Figure 1;

Figure 5 is an enlarged detail sectional view showing the valve means used in the invention;

Figure 6 is an enlarged detail sectional view showing the manner in which the explosive charges are mounted on the hollow member;

Figure 7 is a vertical sectional view taken substantially on the plane of section line 77 of Figure 6; and

: nited States atent Figure 8 is a fragmentary vertical sectional view of the lowering means in modified form.

Referring now to the drawings in detail, wherein, for the purpose of illustration, there is disclosed a preferred embodiment of the present invention, the numeral 10 represents an elongated hollow, preferably cylindrical member having a removable lower end or rounded nose element 12 and a removable upper end or head element 14.

The member 10 is formed with a plurality of openings 16, the outer ends of which are enlarged to provide seats for abutments or stop rings 18. Explosive cartridges or jet shots 20 are slidably received in the openings 16 and include enlarged flat outer ends 22 and tapered bases supporting guide lugs 24 that will engage the abutments 18 to limit sliding movement of the cartridges into and out of the member 10. Sealing rings or gaskets 26 are mounted in the openings 16 against the abutments 18 to prevent the passage of a fluid through the openings 16 and about the cartridges.

A chemically filled or gas filled tube 28 is releasably supported within the head 14 by a bracket 30 of any suitable type. The head 14 is formed with a downwardly and inwardly inclined aperture 32 that slidably receives a plunger or pin 34 whose inner pointed end contacts the tube 28. The outer end of the plunger 34 contacts a cam or eccentric 36 that is pivoted within a recess 38 in the outer surface of the head 14 by a horizontal pin 40 which extends through the walls of the recess 38 and the cam 36. The cam 36 is integrally formed with a radially projecting cam surfaced finger 42 whose lower edge is convex and whose upper edge is concave for a purpose later to be more fully described.

A plurality of circumferentially spaced feeler members or collar finders 44 are pivoted to the head 14 by horizontal pins 46 and include fingers 48 shaped similarly to the finger 42 and which are formed with concave upper edges and convex lower edges.

A flat spring 56 is secured to the head 14 and bears against the cam 36 to urge the cam 36 and finger 42 toward a lowered position. After the cam 36 has been lowered, the spring 54 will snap against a shoulder 52 on the cam and yieldingly retain the cam 36 and the finger 42 lowered.

An electric cable 54 extends through the neck portion 56 of the head 14 and supports an electric type dynamiting cap 58, of any well-known construction, at its lower end. A prima cord or explosive cord 60 is attached to the cap 58 and is trained back and forth through eyes 62 attached to the inner ends 24 of the cartridges 20.

The head 14 is formed with an inlet port 64 in which a spring 66 is mounted. The outer threaded end of the port 64 receives a sleeve 68 having a rubber ball seat 70 in its inner end. A ball valve 72 is mounted in the opening 64 and is normally supported against the seat 70 by the spring 66. Fluid under pressure in the member 19 attempting to leave the member through port 64 will force valve 72 against the seat 7%, whereas fluid entering the port 64 from outside the member 10 will force valve 72 against spring 66 and the fluid may enter the member 10.

The hydraulic action jet gun aforedescribed is simple in operation in that the hollow space in the gun or member 10 is equal in pressure to any outside pressure to which it may be subjected. The jet shots are the same as pistons and remain in place until the inside pressure of member 10 is greater than the outside pressure, causing the jet shots to extend out to the confined limits of the pipe casing or hole to be shot.

The jet gun is made of heavy tubing or expendible material with special type cap 14. This cap 14 is made the same as any other electric type jet gun with the addition of the valve structure, shown in Figure 5, that will tend to permit the pressure in the gun to remain equal to the pressure outside the gun prior to the forcing of the gas tube. The gun can be filled to near the top with water before running it in the hole and as the gun is lowered and outside pressure becomes greater than the inside pressure, fluids are let into the gun through the valve.

The gun, having equal pressure inside and outside, has additional pressure added to the inside by releasing chemicals in the tube 28 which, when added to the water inside of the gun, releases a gas causing a pressure to be generated, thereby causing additional pressure to be created in the chamber of member it), and this additional pressure causes the piston-like jet shots to move outward in a horizontal position to a fixed point, and when all jet shots are fully extended, each jet shot is in absolute contact with the walls of the casing or hole to .be shot.

Obviously, the capsule may be filled with a suitable gas to fill the chamber of memmber 10 without having a chemical that reacts with water or a liquid, such as the capsules used ininfiating life belts or rafts.

Action of jet gun in hole The jet gun is loaded the same as any other gun excepting piston like jet shots are installed with rings in place which seals pressure from inside. Rings 2. on jet shots l ccp jet shots from moving inward. The bottom of the gun is blanked oil by being plugged by the nose 12. The top is installed and made as shown on the attached drawing. Water is put in the annular space in the gun to a point above the last jet shot. The cap is screwed on, and inside the cap is placed the chemical bottle 28 held in place by the holder 36. The plunger 34 is in place and collar finders 43, 42 are in such a position that when pulling upward, the points engage in the small spaces between the make-up J of two joint C. Spring is resting against finder so when the finder has performed its purpose, the spring acting against a shoulder 'holds'the finder in a downward position, eliminating any danger.

The gun is lowered into the hole by means of the cable to a. point near the desired shooting point. For correction of measurements, several collars are located and upon reaching the collar near to the perforating point, the collar finders are engaged and the gun is pulled upward, causing the eccentric motion of the collar finder to move (caused by the action of the off-center pivot) in a downward position. This in turn pushes the plunger against the bottle containing the chemical, breaking same; thereby com bining two elements capable of generating gas or additional pressure. The equalizing valve stays closed and all additional pressure generated by the two elements stays within the limits of the gun. The gas generated causes a pressure to be built up within the confined limits of the gun, causing these parts movable to try to equalize the pressure by expanding or moving out. In this gun, the jet shots are not fixed and will be allowed to move in an outward position as they will act as a piston due to the 0 ring or packing 26 being effective and holding greater pressure within the gun chamber, allowing the jet shot bodies to move outward to within the confined limits of the hole to be shot. In the event the hole to be shot is larger than anticipated, the shots will be limited as to tl eir horizontal movement by an arresting device.

The gun, having been spotted at the place to be shot, awaits the time until the chemicals have had an opportunity to create the extra pressure which has forced or pushed out the shots to the walls or limits of expansion. These shots, thereby coming in contact with the walls of the hole, are discharged the same as any electrically fired jet type gun. Shots are made of disintegrating material and leave the gun free to be removed from the hole.

in the event, for any reason, the gun has to be removed from the hole without having been shot, a device shall be installed at the top of the gun, such as a shear pin or releasing valve, so a hard pull on the line will cause the extra pressure within the chamber to be released to the outside of the gun, thereby causing equalizing of pressures. The removal of the gun will then be easy, in that the jet shots will be pushed back in the walls of their original place, this action being caused by bumping against the side of the pipe.

Attention is directed to Figure 8 to illustrate the device in slightly modified form and more specifically, an alternative method for attaching the lifting cord or cable 54a to the head 14a. in this embodiment, the lower end of the cable 54a supports a cylinder 58a having a reduced lower end 58b that slidably enters a guide ring 59 carried by the head 14a.

The head 14a is provided with a guide bore 61 that slidably receives the cylinder 58a and a coil spring 63 embraces the lower end of the cable 54a and is biased between the cylinder 58:: and the upper wall of the bore 61.

A transverse recess 65 intersects the bore 61 and slidably receives a shear pin 67 that is urged into a recess 69 in the cylinder 55a by a spring 71 in the reces 65.

A vertically inclined passage 73 in the head 14 communicates with the bore 61 and is normally closed by the cylinder 58a. A sealing ring 75 is located in a peripheral groove in the wall of the bore 61 and surrounds the cylinder 53a.

A hard upward pull on the cable 54a will shear the pin 67 and permit gas in the head 14a and the member 10 to pass from the member 10 through bore 61 and passage '73, it being understood that pressure in the member 10 is insulficient to cause a shearing of the pin 67.

The valve structure S shown in Figure 8 is identical to the valve structure shown in Figure 5 in order to permit an under pressure to enter the head portion 14a.

The tube 28 preferably contains a chemical that, when released, mixes with the fluids in the gun, and the reaction from the mixture of these chemicals causes a gas to be formed, thereby generating the extra pressure needed to move the piston-like jet shots.

The jet shot 20 includes a booster shot B, an explosive charge E and a copper lining .C, this being the usual construction of shots used to perforate casings.

Having described the invention, what is claimed as new is:

1. A hydraulic acting jet gun comprising a hollow member having a plurality of openings therein, a cartridge slidably received in each of said openings, means mounted in said member for filling the member with a gas to move the cartridges partially out of said member, movable means carried by said member for anchoring said member adjacent a target and actuating said first-mentioned means, means connected to said cartridges for setting off said cartridges while they are held exposed from said member, and a valve means carried by said member to permit the pressure within said member to equal the pressure of a fluid within a easing into which the member is lowered.

2. A hydraulic acting jet gun comprising a hollow member having a plurality of openings therein, a cartridge slidably received in each of said openings, means mounted in said member for filling the member with a gas to move the cartridges out of saidmember, movable means carried by said member for anchoring said member adjacent a target and actuating said first-mentioned means, and means connected to said cartridges for setting off said cartridges as a unit, said actuating means including a-plunger slidably carried by said member, and a cam carried by said member and engaging said plunger.

3. The combination of claim 2 wherein said cam includes a radially projecting tapered portion adapted to engage the lower end of a section of a casing upon an upward pull on the member after the portion has passed the lower end of the section.

4. An apparatus for perforating a casing comprising an elongated hollow member having a plurality of transverse openings, an explosive cartridge slidably received in each of the openings and movable into and out of said member, chemical means for filling the member with a fluid under pressure for moving the cartridges out of the member and against the inner wall of a casing in which the member is being lowered, said chemical means comprising, a gas filled capsule mounted in said member for filling the member with gas in order to move the cartridges out of said member when the capsule is punctured, and means movably carried by said member for anchoring the member adjacent a target area and simultaneously puncturing the capsule.

5. An apparatus for perforating a casing comprising an elongated hollow member having a plurality of transverse openings, an explosive cartridge slidably received in each of the openings and movable into and out of said member, chemical means for filling the member with a fluid under pressure for moving the cartridges out of the member and against the inner Wall of a casing in which the member is being lowered, said chemical means comprising, a gas filled capsule mounted in said member for filling the member with gas in order to move the cartridges out of said member when the capsule is punctured, movable means supported solely by said member for anchoring the same against movement in one direction and simultaneously puncturing the capsule, and means connected to all of said cartridges for exploding the cartridges as a unit.

6. The combination of claim 4 and valve means carried by said member preventing the exit of gas from the member and permitting fluid under pressure greater than the pressure of fluid in the member to enter the member.

7. An apparatus for perforating a well casing comprising an elongated hollow member having a plurality of transverse openings, an explosive cartridge slidably received in each opening, sealing means in each opening engaging the outer peripheries of the cartridges and the walls of the openings, pressure creating means within the member for moving the cartridges outwardly from the openings and into engagement with the inner periphery of a well casing, a lifting cable slidably secured to the upper end of said member, a shear pin securing the cable to the member to restrict sliding movement of the cable relative to the member, the upper end of said member having a relief port therein blocked by said cable when the cable is held against sliding by said shear pin, said port being opened as the cable is jerked relative to the member to shear the pin whereby pressure in the member will be relieved, and means connected to the cartridges for firing the cartridges after the cartridges have been moved outwardly from the member through the openings.

References Cited in the file of this patent UNITED STATES PATENTS 1,288,107 Messer Dec. 17, 1918 1,641,483 Greene Sept. 6, 1927 2,208,780 Witt July 23, 1940 2,210,125 Raymond Aug. 6, 1940 2,307,729 Foster Ian. 5, 1943 2,373,006 Baker Apr. 3, 1945 2,399,211 Davis et al Apr. 30, 1946 2,667,836 Church et a1. Feb. 2, 1954 

